Paint gun



Sept 15, 1925 1,553,709

J. D. MURRAY PAINT GUN Filed Feb. 25 1924 ATTORNEY" was Sept. 15, i925.

JOHN D. MURRAY, SAN FRANCISCO, CALIFORNIA.

PAIN '1. GUN.

' mime ma February as, 1924. Serial at. 094,571.

To all whom it may concern:

Be it known that I, JOHN D. MURRAY, citizen of the United States, residing at the city and county of San Francisco and State of California, have invented certain new and useful Improvements in Paint Guns,of which the following is a specification.

. maintained portable body formed wi This invention relates to a spray gun designed primarily' for the application of paint or other mixtures by mechanical means. p

The invention has for its principal objectsw-To provide a body for receivingthe material to be applied and having a discharge opening which is controlled by a normally unseated needle valve, and which is adapted to be seated by the application of pressure on a controlling trigger associated therewith; to provide a needle valve structure controlling a discharge orifice, which valve is capable of lineal movement and axial rotation, its lineal movement con trolling the discharge of the material from the orifice, and its axial rotation regulating the liquid volume for mixing with. the air; to provide a structure which is normally unseated by spring pressure and seated by manual pressure, and the position of which is adapted to be varied independently of the operation of the manually depressing means, and without varying the tension of the spring pressure.

The invention consists primarily in a th a mixing chamber, having an inlet and a discharge orifice the same containing a controlling valve, the axial rotation of which is adapted to vary the fluid volume admitted into the chamber and the lineal movement of which is adapted to control the material discharged through the discharge orifice, there being provided a suitable hand-grip construction and a trigger for manual operation to lineally move the valve, there being also provided a means forvarying the lineal position of the valve in the chamber without resorting to its movement bythe operation of the trigger, and a separate valve for regulating the air volume admitted into the mixing chamber- The invention also consists in providing a means for closing the communication between the air supply and mixing chamber when pressure on the trigger is released.

- With the above mentioned and other ob-- jects inview, the .invention consists in the .positione or sacrificing any 0 the advantages 0 the invention.

To more fully comprehend the invention, to the accompanying reference is directed drawings, wherein Fig. 1 is a view in side elevation partly in section of the preferred embodiment of my invention.

Fig. 2 is a longitudinal sectional view taken on line 2-2 of Fig. 3.

'Fig. 3 is a sectional View on line 3-3 of Fig. 2, and Fig. 4 is a cross sectional the largest diameter of the taken on line 4-4.- of Fig. 2.

Referring more particularly to the sevview through needle valve,

eral views of the drawings wherein like characters of reference designate corresponding parts, 1 indicates afbarrel or body of a portable spraying apparatus commonly referred to as the gun has detachablysecured t ereto and extending downwardly from one end thereof a hand-grip portion or stock 2. The handgrip is tubular in form afiording a channel 3, the inlet end of which is connected by a suitableconpling 4 for the supply of fluid preferably air under pressure. The upper end of the channel 3 connects through a bore 5 in the barrel or body 1 w'th one end of a mixing chamber 6, said chamber being open at one end and said u per end carryt pe, and the sameorifice 8 which terminates in an atomizing chamber 9. In the chamber is .loosely mounted a ball 10 loosely confined between the stop pins 11 disposed transversely of the atomizmg chamber. .Over the dischar end of the atomizmg chamber, when it is desired to apply a at stream, is adapted to be a transversely slotted tip 12, commonly known as the gas tip ty and said tip andmember 7 are nemova l y retained in position at the open end of the chamber 6 by a collar 13 threadedly connected as at 14 with the discharge end of the barrel or body 1. Intermediate the point of connection of the bore 5 with the chamber and the I outlet end of said mixing chamber, I introduce into the mixing chamber a bore 15 formed within a lateral extension 16 depending from the barrel or body 1 and said bore connects with the supply or paint or other material to be applied and intermixed with the air. To contract the air volume in the channel 3, I rotatably mount in a recess- 17 a chambered air valve 18, the stem 18 of which extends through a gland 18 and stufiing nut 18 and mounts on its end a hand knob 18. Within the mixing chamber 6 there: is mounted with a snug fit a suitablevalve consisting of the body 21 terminating in a needle end 20, and a conical valve 20' from 'which extends a stem22, the body being longitudinally grooved as at 23, and said needle end is disposed in alignment with the orifice 8. The body 21 overlies the point of intersection of the bore 15 and the chamber 6 and its exterior is transversely cut away as at 24. The stem 22 extends rearwardly from the body 1 through ,a member 24 having a tapered seat 23 with which valve 20' co-operates and also through a packing gland 25 held in position by a stufling nut 25. At a point exteriorly of said stufiing nut the stem is provided with a threaded portion 26 and at its extreme rear end carries a knurled head 27.

- .valve is normally maintained unseated by the action of a coiled spring 28 abutting at one end against the stufiing nut 25 of 'the .packing, and at its opposite end abutting against the wall of a collar 30 threadedto the portion 26 of the stem. To longitudinally move the valve against the action of the spring 28 to closed position, I provide a bifurcated lever construction 31 fulcrumed at 32 to the rear end of the body or barrel and the forward end of the lever construction is fashioned to provide a trigger 33 disposed in a convenient position in advance of and near the upper end of the hand-grip portion 2. The opposite end of the leverconstruction is connected through a sliding fulcrum joint 34 with opposite sides of the collar 30. a

The spring 28 normally maintains the needle valve 20 unseated and a manual depresslon of the trigger 33 will cause the /forward movement of the needle valve to close the discharge orifice The valve, it

will be observed, is also capable of axial rotation within the bore, and its axial position controls the painter fluid volume admitted mto the chamber 6 through the bore 15, :asit will be apparent that when the cutaway portion 24 fullyv registers with the discharge end of the bore 15, a full paint volume is admitted into the chamber, but that on axialrotation said body 21 serves as a cut-01f valve to instantly control the admission of paint into the chamber through thebore 15. It will also be apparent that This relative to the discharge orifice 8 may be regulated by the axial rotation of the valve stem 22, and that this is accomplished without varying the tension on the spring 28, -as the valve stem is adjusted within the collar'30. d

On the full retraction of the valve due to the action of the spring 28 after the release of pressure from the trigger the valve 20 engages the seat 23' and precludes the flow of paint rearwardly from the chamber 6. The member 24: snugly fits the walls of enlarged chamber 36 and its bore is of a diameter slightly greater than that of the stem 22 to afford an air passage into the mixing chamber 6.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent of the United States is 1. A spray gun including a body provided with a mixing chamber having a discharge orifice, a nozzle thereover, said body provided with independent air and liquid inlets communicating with the mixing chamber, a valve within the mixing chamber and capable of movement in one direction for controlling the mixture volume discharging from the nozzle, and of movement in another direction for regulating the liquid volume admitted into the mixing chamber.

2. A spray gun including a body provided with a mixing chamber having adischarge orifice, a nozzle thereover, said body provided with independent air and liquid inlets communicating with the mixing chamber, and a single valve adapted for longitudinal and axial movement to control the mixture proportion discharging from the nozzle, and the liquid volume admitted into said mixing chamber.

3. A spray gun including a body provided with a mixing chamber having a discharge orifice, a nozzle thereover, said body provided with independent air and liquid inlets communicating with the mixing chamber, and a single valve capable of axial and longitudinal movement within the chamber, one movement controlling the proportion of mixture and the other controlling the volume dischargingfrom the nozzle.

4. A spraygun including a body rovided with a mixing chamber having a ischarge orifice, a nozzle thereover, sald body provided with independent air and liquid inlets communicatingrwith the chamber, a needle valve reciprocably mounted within the chamber for controlling the mixture discharge through the nozzle, a hand-grip for the body, means for normally maintaining said valve unseated, said valve adapted for axial rotation to control the mixture proportion and a trigger adapted for operation 7 charge through the nozzle,

- normally maintaining the valve i with A ing into the chamber,

5. A spray gun including a body provided with a mixing chamber havin orifice, a nozzle thereover, said bod provided with independent air and liqui inlets communicating with the chamber, a needle valve reciprocably mounted within the chamber for controlling the mixture disand capable oi mixture proporgrip for the nozzle, a spring for unseated, a trigger for operation to oppose said spring to seat the valve, and means for varying the operative movement of said valve without varying the tension of said spring.

6. A spray gun including a body having amixing chamber therein-terminating in a discharge opening, a pair of inlet channels opening thereinto, a needle valve mounted axial rotation to control the tion, a handfor reciprocation and axial rotation within said chamber for controlling the discharge opening and for-varyin the efl'ective area of the discharge end 0 one of said'inlet channels. 1 v

'7. A spray gun including avbody'provided in a discharge orifice, an inlet channel opena needl valve mounted for axial rotation and reci ocatibnwithin said chamber, the reci rocation of said" valve controlling the disc1arge orifice and its axial rotation varying the effective area of the discharge end of said inlet channel.

8. A spray gun including a body pro vided with a mixing chamber therein terminating in a discharge orifice, an inlet channel opening into the chamber, a longitudinally grooved ne'edle valve slidably fittin within the chamber, means for moving t e valve a discharge a mixing chamber therein terminating longitudinally to control the discharge opening, said valve provided with atransvers depression adapted on the axial rotation of the valve for registering with the end of the discharge channel to vary the eflective area of its discharge end, a spring for normally maintaining said needle valve unseat ed, a collar threaded on the stem of the valve and against which the spring bears, a trigger for operation to close the valve, and a fulcrum connection between the trigger body and collar.

9; A spray gun including a handled body provided with a chamber terminating in an outlet orifice, a channel communicating with the chamber for supplying fluid thereto, a

"normally unseated needle valve for controlaction of the spring, and a fulcrum connection between the trigger and collar. 7

10. A spray gun including a handled body provided with a chamber terminating in an outlet orifice, a channel communicating with the chamber for supplying fluid thereto, a needle valve for controlling the discharge fluid through the outlet orifice, a spring for normally maintaining the valve seated and a trigger associated with the valve for operation to close the same against the action of the spring, said trigger being disposed in advance of the body handle. In testimony whereof I have signed my.

name to this specification.

JOHN D. MURRAY. 

